Highly transparent, impact-resistant modified polyvinyl chloride molding compositions

Abstract

Highly transparent, impact-resistant molded articles can be produced from a molding composition, comprising: (1) a major portion of polyvinyl chloride or a copolymer comprising at least 70% by weight of vinyl chloride units; and (2) an amount effective to impart impact resistance of: (a) at least one homopolymer of an acrylate monomer having the formula ##STR1## wherein R is a straight-chain or branched alkylene residue of 3-8 carbon atoms, optionally interrupted by 1-2 ether oxygen atoms, wherein the straight-chain portion of said alkylene residue contains at least 3 carbon atoms; or (b) a copolymer of said acrylate monomer and up to 30% by weight of at least one acrylate ester of a C 4-12 aliphatic alcohol.

What is claimed is: 
     
       1. A modified polyvinyl chloride molding composition, comprising (1) a major proportion of polyvinyl chloride or a copolymer comprising at least 70% by weight of vinyl chloride units; and (2) an amount effective to impart impact resistance and high transparency of (a) at least one homopolymer of an acrylate monomer having the formula ##STR6## wherein R is a straight-chain or branched alkylene residue of 3-8 carbon atoms, optionally interrupted by 1-2 ether oxygen atoms, wherein the straight-chain portion of said alkylene residue contains at least 3 carbon atoms; or (b) a copylymer of said acrylate monomer and up to 30% by weight of at least one acrylate ester of a C 4-12  aliphatic alcohol. 
     
     
       2. A molding composition according to claim 1, wherein said acrylate homopolymer or copolymer imparting impact resistance has a weight average molecular weight of about 10 4  to about 5×10 8 . 
     
     
       3. A molding composition according to claim 2, wherein said weight average molecular weight is about 5×10 4  to 5×10 7 . 
     
     
       4. A molding composition according to claim 1, wherein said effective amount is about 1-30% by weight, based on the mixture of said polyvinyl chloride or vinyl chloride copolymer and said acrylate homopolymer or copolymer. 
     
     
       5. A molding composition according to claim 4, wherein said effective amount is about 3-15% by weight. 
     
     
       6. A molding composition according to claim 1, wherein said acrylate homopolymer or copolymer is crosslinked with about 0.1-2% by weight of a bis-ethylenic crosslinking agent. 
     
     
       7. A molding composition according to claim 6, wherein said crosslinking agent is a lower alkylene glycol dimethacrylate or diacrylate. 
     
     
       8. A molding composition according to claim 1, wherein R is propylene, butylene or pentylene. 
     
     
       9. A molding composition according to claim 8, wherein said acrylate polymer is a homopolymer. 
     
     
       10. A molding composition according to claim 8, where said acrylate polymer is a copolymer; and wherein said acrylate ester of a C 4-12  aliphatic alcohol is n-butyl or 2-ethylhexyl acrylate. 
     
     
       11. In a molded polyvinyl chloride article produced by molding a molding composition comprising a major proportion of polyvinyl chloride or polyvinyl chloride copolymer, the improvement wherein said molding composition is a molding composition according to claim 1; whereby said molded article has high transparency and high impact resistance. 
     
     
       12. A molded article according to claim 11 having a higher transparency than a molded bulk polyvinyl chloride article. 
     
     
       13. A method of imparting high impact resistance to a molded polyvinyl chloride article, comprising molding said article from a molding composition according to claim 1. 
     
     
       14. A method according to claim 13, wherein the amount and type of polyacrylate polymer are such that the resultant molded article has a higher transparency than a molded bulk polyvinyl chloride article. 
     
     
       15. A molding composition according to claim 1, wherein said polyvinyl chloride is grafted onto said acrylate homopolymer or copolymer. 
     
     
       16. A process for preparing a molding composition according to claim 1, comprising the step of polymerizing vinyl chloride in the presence of said acrylate homopolymer or copolymer and in the presence of at least one radical catalyst.